Chocolate has the disadvantage that the better the quality of the chocolate, the more easily the influence of temperature affects it. Conventional chocolate becomes soft at above 28.degree. C., and loses shape retention at above 32.degree. C. Thus, in order to overcome such disadvantage, a number of investigations on heat-resistant chocolate have conventionally been carried out.
A rough classification of conventional technologies relating to heat-resistant chocolates may give the following two types:
(1) oils and fats used have a high melting point, PA0 (2) a framing structure is formed with solids other than oils and fats.
Among them, there are the following methods, for example, as means for forming the framing structure of above type (2), which are used alone or in combination in order to increase heat-resistance of chocolate:
a. hydrophilic substances (several kinds of sugar and the like) are used, PA1 b. water or an emulsion is used, PA1 c. a chocolate is treated at a high temperature, PA1 d. a part of chocolate or materials thereof is pre-ground.
However, in the conventional technologies, all heat-resistant chocolate obtained have problems of quality, being unsuccessful as practical products.
Namely, according to said method (1), oils and fats of high melting point are used, so that a waxy mouth-feel is provided, which lacks a smooth melt feeling in mouth characteristic to chocolates. In addition, according to said method (2), a framing structure is given, so that a crunchy and brittle mouth-feel is provided, which also lacks a smooth melt feeling in mouth and a good snap property.
Attempts to provide heat-resistant chocolates by forming a frame structure with solid substances other than oils and fats are described, for example, in Japanese laid-open patent application No. 57-115140. In this prior art, there is disclosed "a heat-resistant chocolate composition containing particles which form a "water/lipid type" emulsion comprising lipid at least a part of which is solidified, being dispersed in a chocolate composition in addition to usual chocolate components."
However, a chocolate of good quality may not be produced by means of this technology. A chocolate produced by this technology has large particles and a rough mouth-feel in which the framing structure gives a munchy mouth-feel to give a problem in quality. In this technology, at least a part of lipid substances which construct an emulsion of water/cacao butter type containing lecithin is solid lipids. In fact, for the purpose of stabilizing the emulsion, the content of solid lipid is not less than 30%. Although the solid lipid which may make the quality low is used in a high content, this emulsion is practically very unstable. In case of mixing with a chocolate, on account of variation or the like of temperature condition and agitation condition, a partial agglomeration of solid particles of chocolate (especially sugar) takes place, which becomes a cause of roughness. Moreover, the water phase in the W/O type emulsion is pure water, so that it affects to solid particles of chocolate too excess, resulting in a munchy mouth-feel of obtained chocolate.